1. Field of the Invention
The present invention relates to a film deposition method and a film deposition apparatus where a silicon oxide film is deposited on an upper surface of an object to be processed such as a semiconductor wafer.
2. Description of the Related Art
In order to fabricate semiconductor integrated circuits, various processes such as film deposition, etching, oxidation, diffusion, and alteration processes are carried out with respect to a semiconductor wafer (referred to as a wafer hereinafter) made of silicon or the like. For example, the film deposition process is carried out in a single-wafer film deposition apparatus disclosed, for example, in Patent Document 1 below and in a batch-type film deposition apparatus disclosed, for example, in Patent Document 2. As shown in FIG. 1, the batch-type film deposition apparatus has a wafer boat 4 that is accommodated in a process tube 2 and holds plural wafers serving as objects to be processed in a multistage manner, distribution nozzles 8, 10 that extend along a vertical direction within the process tube 2 and supply source gases toward the wafer boat 4, an evacuation opening 12 provided in a lower portion of the process tube 2, a vacuum evacuation system 14 including a vacuum pump 16, and a heating part 6 that surrounds the process tube 2.
In addition, when a silicon oxide film is deposited on the wafers in the film deposition shown in FIG. 1, the wafer boat 4 that holds plural wafers is accommodated in the process tube 2, and the wafers are heated to about 600° C. by the heating part 6. A silicon-containing gas as a source gas is supplied to the distribution nozzle 8 from a gas supplying part 7, and then supplied toward the wafers W from plural gas ejection holes 8A provided in and along the longitudinal direction of the distribution nozzle 8. In addition, ozone gas as a reaction gas is supplied to the distribution nozzle 10 from the gas supplying part 7, and then supplied toward the wafers W from gas ejection holes 10A provided in and along the longitudinal direction of the distribution nozzle 10. On the other hand, the interior of the process tube 2 is evacuated by the vacuum evacuation system 14, and maintained at a predetermined pressure. The silicon-containing gas and the ozone gas are reacted, and thus the silicon oxide film is deposited on the wafers W.
In addition, another film deposition method may be carried out where the silicon-containing gas and the ozone gas, which is an oxidizing gas, are alternately repeatedly supplied by alternately opening and closing an on-off valve 88 and an on-off valve 10B of the gas supplying part 7, thereby allowing the source gas adsorbed on the wafers W to react with the ozone gas and depositing the silicon oxide film on the wafers W. This film deposition method is advantageous in that properties of the film obtained are relatively excellent and the film deposition can be carried out at relatively lower temperatures.    Patent Document 1: Japanese Patent Application Laid-Open Publication No. H09-077593.    Patent Document 2: Japanese Patent Application Laid-Open Publication No. 2009-246318.    Patent Document 3: Japanese Patent Application Laid-Open Publication No. 2006-054432.